Exploring the histogenesis of STK11 adnexal tumour using electron microscopy

• Published in: Virchows Archiv : an international journal of pathology Vol. 485; no. 4; pp. 683 - 690
• Main Authors: Mascaro, Nuria, Aboelnasr, Lamia Sabry, Masood, Motasim, Yague, Ernesto, Moran, Linda, El-Bahrawy, Mona
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-10-2024; Springer Nature B.V
• Subjects: Adult; AMP-Activated Protein Kinase Kinases; Cell differentiation; Electron microscopy; Female; Fibers; Genital Neoplasms, Female - genetics; Genital Neoplasms, Female - pathology; Genital tract; Histogenesis; Humans; Medicine; Medicine & Public Health; Middle Aged; Nuclei (cytology); Nucleoli; Original; Original Article; Pathology; Peutz-Jeghers syndrome; Peutz-Jeghers Syndrome - genetics; Peutz-Jeghers Syndrome - pathology; Protein Serine-Threonine Kinases - genetics; Sex; Sex Cord-Gonadal Stromal Tumors - genetics; Sex Cord-Gonadal Stromal Tumors - pathology; Tubules; Tumors; STK11 adnexal tumour; Electron microscopy; Peutz-Jeghers syndrome
• ISSN: 0945-6317; 1432-2307; 1432-2307
• DOI: 10.1007/s00428-024-03763-2

STK11 adnexal tumour is a recently described female genital tract tumour, usually identified in a paratubal location, often associated with Peutz-Jeghers syndrome (PJS) and with
STK11
gene alterations identified in most of the cases. Morphologically, this tumour is composed of cells arranged in a variety of patterns, including cords, trabeculae, tubules and cystic and acinar structures. The cells are only moderately pleomorphic and mitotic activity is variable. As tumour cells express epithelial, sex cord stromal and mesothelial markers, STK11 adnexal tumour may be of sex cord stromal, epithelial or mesothelial origin; a Wolffian origin has also been suggested. We report the ultrastructural features of two STK11 adnexal tumours and compare their ultrastructural features with those of other sex cord stromal tumours, a granulosa cell tumour cell line, as well as the known ultrastructural features of epithelial, mesothelial and Wolffian cells. On ultrastructural examination, two STK11 adnexal tumours showed an admixture of elongated cells with regular elongated nuclei and polygonal cells with nuclei showing markedly irregular outlines and prominent nucleoli. Extracellular collagen fibres were identified. These are common ultrastructural features of sex cord stromal tumours, principally sex cord tumour with annular tubules; no ultrastructural features of epithelial, mesothelial or Wolffian cells were found. These findings in conjunction with the shared clinical and genetic association with PJS and shared molecular changes in
STK11
gene suggest that STK11 adnexal tumour represents a poorly differentiated sex cord tumour.